In the case of these micro connecting elements, the electrical contacting takes place on contact areas of the semiconductor chip and contact terminal areas of the wiring substrate and/or a printed circuit board and/or a leadframe by an ultrasonic friction-welded connection, the micro connecting elements of the bonding wire a few micrometers thick entering into a low-melting eutectic alloy with the coating of the contact areas with terminal areas. However, these wire connections have the disadvantage in high-frequency applications that they form parasitic inductances. In an approximate estimate, this parasitic inductance is around 1 nH/mm and can lead to stray signals being coupled into the signal flow of the high-frequency semiconductor device. There may also be an antenna effect, which leads to the transmission of electromagnetic waves.
In the case of semiconductor devices with bonding wires pressed into a plastic package molding compound, parasitic parallel capacitances which impair the high-frequency transmission characteristics of such semiconductor devices form, depending on the dielectric constant of the plastic package molding compound. This is manifested by electrical losses, a reduction of the cutoff frequency and changes in the adaptation of input circuits and output circuits. These effects, which are attributable to the use of bonding wires, are undesired and make it more difficult to realize high-frequency electric circuits with corresponding semiconductor devices.
These disadvantages can be partly reduced by the use of flip-chip contacts, with which the parasitic inductances are smaller. It is also attempted to achieve shorter signal paths. However, the technique of flip-chip contacts also has its limits with respect to high-frequency technology, since not all applications allow themselves to be implemented as flip-chip semiconductor devices owing to the design of the circuits. In particular if relatively long electrical signal paths become necessary for the electromagnetic waves, the flip-chip method is unsuccessful. Furthermore, flip-chip contacts are only suitable to a limited extent for operating at high frequency, since they neither have waveguide characteristics nor are protected in the event of electromagnetic fields being coupled in.
For these and other reasons, there is a need for the present invention.